Carrier and mount

ABSTRACT

A carrier and mount assembly for a heavy vehicle disc brake. The assembly includes a carrier having a first location formation formed therein, a mount having a second location formation formed therein, wherein the second location formation is aligned with the first location formation, and wherein the carrier is mounted to the mount via two or more fasteners that extend in a direction substantially parallel to a direction of insertion or removal of a friction element into or from the carrier. There is also a locator positioned in the first and second location formations to enable the carrier and mount to be assembled in the correct position, wherein the locator is at least a close fit to the first and second location formations.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to European Patent Application No.12177731.2 filed Jul. 24, 2012, the disclosure of which is incorporatedin its entirety by reference herein.

TECHNICAL FIELD

The present invention relates to a method of mounting a carrier of adisc brake to a mount, and/or a carrier and mount assembly.

BACKGROUND

Disc brakes, for example air actuated disc brakes are commonly used forbraking heavy vehicles such as trucks, buses and coaches. There are manytypes of disc brakes available. An example of one of the many types ofpneumatic disc brakes is shown in FIG. 1.

Referring to FIG. 1, the disc brake 110 has a carrier 112 that carries acaliper 114. The carrier also carries friction elements 122 such thatone friction element is positioned on each side of a rotor 116 of thedisc brake 110. An air actuator is provided for moving an inboardfriction element into frictional contact with the rotor 116 via anactuator mechanism (not shown). The rotor 116 is fixed in aninboard-outboard direction, so that when the inboard friction element ispushed towards and contacts the rotor 116, further pushing of theinboard friction element towards the rotor 116 causes the caliper 114 tomove inboard. As the caliper 114 moves inboard it moves the outboardfriction element towards the rotor 116 clamping the rotor 116 betweenthe outboard and the inboard friction elements 122 and thereby effectingbraking by frictionally inhibiting rotation of the rotor 116.

In use, the disc brake is mounted to an axle of a vehicle. This may beachieved by connecting the carrier to a mount on the axle, typically viaa bracket welded to the axle. Bolts arranged parallel to an axis ofrotation of the rotor secure the carrier to the mount.

Alternatively, for example where an axle has a flange for connection toa drum brake, the carrier is generally attached to a separate mount,often referred to as an adapter plate, and the separate mount isconnected to the flange. Axial mounting may result in difficulty inaccessing bolts to assemble/disassemble the brake, as well as increasethe weight of the brake due to the material doubling at the interfacebetween the mount and carrier. Accordingly, tangential mounting may beused, i.e. the carrier is mounted to the mount via fasteners (e.g.bolts) that extend in a direction tangential to the rotor andsubstantially perpendicular to the axis of rotation of the rotor.

Features of the carrier and mount generally enable the carrier to beaccurately mounted to the axle in a direction A parallel to an axis ofrotation of the rotor 116. However, there may be difficulties aligningthe carrier with respect to a rotor of a disc brake. Referring to FIG.2, misalignment of the carrier can result in the rotor 116 and frictionelement 122 being misaligned, such that the friction element 122 isspaced from the rotor by a greater distance 121 at one side of thefriction element than at an opposite side of the friction element. Thismisalignment can result in taper (i.e. uneven) pad wear and/ornon-uniform loading of the caliper mechanism and components. This may beparticularly problematic in brakes where bolts secure the carrier to themount in a tangential or chordal direction (so-called tangential mountcarriers), as there may be no overlap of faces of the carrier and mountin the axial direction to aid alignment. This problem is particularlyproblematic in heavy vehicles rather than lighter vehicles because thelarger dimensions of heavy vehicle brakes tend to amplify the effects ofany misalignment.

SUMMARY

The present invention seeks to alleviate problems associated with theprior art.

In a first aspect of the invention there is provided a carrier and mountassembly for a heavy vehicle disc brake, the assembly comprising: acarrier having a first location formation formed therein, a mount havinga second location formation formed therein, wherein the second locationformation is aligned with the first location formation, and wherein thecarrier is mounted to the mount via two or more fasteners that extend ina direction substantially parallel to a direction of insertion orremoval of a friction element into or from the carrier; and a locatorpositioned in the first and second location formations to enable thecarrier and mount to be assembled in the correct position, wherein thelocator is at least a close fit to the first and second locationformations.

The mounting assembly of the first aspect has been found to easealignment of the carrier to the mount so as to ensure correct alignmentof the carrier to the rotor.

A close fit may be a transitional fit or an interference fit. Forexample, when the close fit is a transitional fit, the fit may have aclearance of between 0 mm to 0.04 mm.

The carrier may be seated on the mount such that planar contactingsurfaces of the carrier and mount extend in a plane substantiallyperpendicular to a plane of a rotor and parallel to an axis of rotationof a rotor of a disc brake.

The first location formation and the second location formation may bepositioned to extend in a direction substantially parallel to adirection of insertion or removal of a friction element into or from thecarrier.

Only one locator may be provided in the carrier and mount assembly.Provision of only one locator has been found to ease assembly whilstsufficiently permitting correct alignment of the carrier and mount toreduce taper pad wear.

The first location formation is a hole formed in the carrier and thesecond location formation is a hole formed in the mount, and the locatoris a peg positioned in the first location formation and the secondlocation formation.

In the present application a hole defines an enclosed channel thatextends fully or partially through a component. For example, a hole mayhave a circular or oval cross section.

The peg may be an elongate cylindrical member. The peg may comprise aknurled portion positioned in one of the carrier and the mount. The pegmay comprise a portion dimensioned to be an interference fit with thecarrier. For example, the knurled portion may be dimensioned to be aninterference fit with one of the carrier and the mount.

The carrier may comprise two holes arranged such that one hole ispositioned on either side of a plane defined by an axis extendingsubstantially parallel to a direction of insertion or removal of afriction element into or from the carrier, and an axis of rotation of arotor of a disc brake. The mount may comprise two holes positioned to besubstantially coaxial with the two holes of the carrier. One of the twoor more fasteners may extend through each of the holes for mounting thecarrier to the mount. For example, the fasteners may be threaded boltsand the two holes may be threaded to mate with the threaded bolt.

The carrier may comprise two further holes arranged such that onefurther hole is positioned on either side of a plane defined by an axisextending substantially parallel to a direction of insertion or removalof a friction element into or from the carrier, and an axis of rotationof a rotor of a disc brake. The mount may comprise two further holespositioned to be substantially coaxial with the two further holes of thecarrier. One of the two or more fasteners may extend through each of thefurther holes for mounting the carrier to the mount. For example, thefasteners may be threaded bolts and the two further holes may bethreaded to mate with the threaded bolt.

The two holes, the two further holes, and the first and second locationformations may be arranged in line in a direction substantiallyperpendicular to an axis of rotation of a rotor of a disc brake, andsubstantially perpendicular to a direction substantially parallel to adirection of insertion or removal of a friction element into or from thecarrier.

The first location formation and the second location formation may bepositioned between one of the holes and one of the further holes.

The carrier and mount assembly may comprise a location hole formed inthe carrier and a location hole formed in the mount. The location holein the carrier and the location hole in the mount may have similardimensions to the first and second location formation. The location holemay be on an opposite side to the first and second location formationsof a plane defined by an axis extending substantially parallel to adirection of insertion or removal of a friction element into or from thecarrier, and an axis of rotation of a rotor of a disc brake.

The locator may be a bush. The bush may extend at least partiallythrough the first and second location formations. The bush may be asplit bush. Use of a split bush eases assembly. An end of the bush thatmay be received in the mount may have a chamfered outer edge. Provisionof a chamfered edge also eases assembly.

The carrier may comprise two holes arranged such that one hole ispositioned on either side of a plane defined by an axis extendingsubstantially parallel to a direction of insertion or removal of afriction element into or from the carrier, and an axis of rotation of arotor of a disc brake. The mount may comprise two holes positioned to besubstantially coaxial with the two holes of the carrier. One of the twoor more fasteners may extend through each of the holes for mounting thecarrier to the mount. For example, the fasteners may be threaded boltsand the two holes may be threaded to mate with the threaded bolt.

The first location formation may be integrally formed with one of theholes in the carrier and the second location formation may be integrallyformed with one of the holes in the mount.

The first location formation may be a portion of one of the holes andthe second location formation may be a portion of one of the holes, andthe first and second location formations may have a larger diameter thanthe remainder of the holes.

The two holes may be threaded to receive a threaded fastener along thelength thereof, excluding the first and second location formations.

The carrier and mount assembly may comprise a further bush positioned toextend at least partially through the other of the two holes formed inthe carrier and mount. The further bush may be a loose fit to the holein the mount. A loose fit may be a fit having a clearance greater than0.04 mm.

The carrier and the mount may include two further holes positioned suchthat one further hole is positioned on either side of a plane defined byan axis extending substantially parallel to a direction of insertion orremoval of a friction element into or from the carrier, and an axis ofrotation of a rotor of a disc brake. The mount may comprise two furtherholes positioned to be substantially coaxial with the two further holesof the carrier. The bushes may be located in the holes nearest an axisof rotation of a rotor.

In a second aspect the invention provides a method of mounting a carrierof a disc brake to a mount, the method comprising: providing a carrierto be mounted having a first location formation; providing a mounthaving a second location formation alignable with the first locationformation; positioning a locator in the first and second locationformation to support the carrier in alignment with respect to the mountso as to correctly position the carrier with respect to the mount; andmounting the carrier to the mount using fasteners that in a mountedposition extend in a direction substantially parallel to a direction ofinsertion or removal of a friction element into or from the carrier;wherein the first and second location formations are formed to be aclose fit with the locator.

The first location formation may be a hole in the carrier and the secondlocation formation may be a hole in the mount, and the first and secondlocation formations may be positioned to be coaxial when the carrier ismounted to the mount. The locator may be a peg, and the method maycomprise positioning the peg in the hole in the carrier, and thenmounting the carrier with the peg to the mount.

Two holes may be provided in the carrier and mount positioned to be oneither side of a rotor, and the two holes may be dimensioned for receiptof the locator. The method may comprise positioning the locator in onlyone of the two holes of the carrier and mount, and then mounting thecarrier to the mount.

Wherein the carrier is mounted to the mount via a fastener at a positionnear the locator and a position further from the locator. The step ofmounting the carrier to the mount may comprise fastening the carrier tothe mount at a position further from the locator, and subsequently at aposition near the locator.

The carrier, mount and locator may be the carrier, mount and locator ofthe carrier and mount assembly of the first aspect.

In a third aspect of the present invention there is provided a method ofmounting a carrier of a disc brake to a mount, the method comprising:providing a carrier or caliper to be mounted having a first locationformation; providing a mount having a second location formationalignable with the first location formation; positioning a locator inthe first and second location formation to support the carrier orcaliper in alignment with respect to the mount so as to correctlyposition the carrier or caliper with respect to the mount; mounting thecarrier or caliper to the mount; and removing the locator from thelocation formation for normal use of the disc brake.

The method of the present invention permits the carrier to be correctlypositioned with respect to the mount in both a direction parallel to anaxis of rotation of a rotor of a disc brake and in a plane parallel to aplane of a rotor of a disc brake. This means that when the disc brakehaving said mount and carrier are mounted to an axle of a vehicle,friction elements of the disc brake are substantially aligned with therotor alleviating the above described problem of taper pad wear andnon-uniform loading of the caliper mechanism and components.

Throughout the present application directions of features of the mountand/or carrier are referred to with respect to a rotor of a disc brakeof which the carrier may be a component thereof. The directions areshown by arrows in FIG. 1 and later described FIG. 3. Direction A is adirection through an axis of rotation of a rotor of a disc brake and issubstantially perpendicular to a plane substantially parallel to aplanar face of the rotor; a direction T is a direction tangential to ato a circle described by rotation of a rotor of a disc brake andgenerally parallel or aligned with a direction of insertion or removalof a friction element into or from the carrier; and a direction R is adirection substantially perpendicular to both of the axes defined bydirection A and direction T respectively (i.e. is generally aligned witha width of the carrier).

The first location formation may be positioned in alignment with thesecond location formation, and then the locator may be positioned in thefirst and second location formation. Alternatively, the first and secondlocation formations may be positioned in substantial alignment, and thestep of positioning the locator in the first and second locationformation may correctly align the first and second location formations.

The mount may be directly connected to an axle, for example by welding,or may be connected to a flange of an axle, for example using bolts.Alternatively, the mount may be part of a steering knuckle on a steeredaxle.

The locator may be a single locator positionable in both the first andthe second location formations. The locator may be a dowel.

The location formations may be locator channels. The location formationsmay comprise a non-threaded surface. For example, the locationformations may comprise a substantially smooth surface.

The first and/or second location formation may be provided on a surfaceof the carrier and/or mount, respectively. The first and/or secondlocation formation may be provided entirely on a surface of the carrierand/or mount, respectively.

The first and second location formations may be positioned in co-axialalignment. Such alignment permits a locator such as a dowel to be moreeasily positioned in both the first and second location formation.

The carrier may be attached to the mount using two or more fasteners.Alternatively, the carrier may be attached to the mount by welding.

The first or second location formation may be a groove formed in arespective surface of the carrier and/or mount. The first and/or secondlocation formations may be linear grooves. The groove may have asubstantially semi-circular cross section.

The first location formation may be a groove positioned to be alignedand in opposition to the second location formation to form a conjoinedlocation formation, to receive the locator. The locator may be a dowel,and the dowel may have a similar cross-section to the cross-section ofthe conjoined location formation. The first and second locationformations may be provided to be in a direction in the plane of rotationof a rotor of the disc brake and substantially perpendicular to an axisthrough a center of rotation of a rotor and substantially perpendicularto a direction tangential to a rotation of a rotor. The method maycomprise providing a first seat adjacent one or more sides of the firstlocation formation and a second seat adjacent one or more sides of thesecond location formation, and positioning the first and second seats inopposition and abutment. The seats may be formed by machining a surfaceof the mount and carrier. The seat can further improve the accuracy withwhich the carrier can be positioned with respect to the mount.

The seats may be in a plane defined by directions A and T, i.e. they maybe chordal with respect to a circle described by rotation of the rotor,and may further be provided either side of an axle, and may be co-planar

The locator may be a component of a clamping device.

Alternatively, the first location formation may be a hole formed in thecarrier and the second location formation may be a hole formed in themount.

The first and/or second location formation may have a non-circularcross-section. In exemplary embodiments, the first and/or secondlocation formation may have a directional component in a directioncorresponding to a plane of rotation of a rotor of the disc brake.

The method may comprise coaxially aligning a bore formed in the carrierand the mount for receiving a fastener for mounting, with the firstand/or second location formation. The first and/or second locationformation may comprise a slot having a directional component in adirection corresponding to a plane of rotation of a rotor of the discbrake. For example, the slot may be rectangular or oval. In suchembodiments, the locator may be a dowel having a rectangular or ovalcross section. Alternatively, the locator may be a dowel having a crosssection substantially similar to the cross section of the hole.

The first location formation may extend partially through the carrierand the second location formation may extend entirely through the mount,or the second location formation may extend partially through thecarrier and the first location formation may extend entirely through themount. Alternatively, the first location formation may extend entirelythrough the carrier and the second location formation may extendentirely through the mount.

The step of mounting the carrier to the mount may use a fastener. Insuch embodiments, the method may comprise the step of using the fastenerto drive the locator through the hole as the fastener is fastened to themount and carrier. The step of mounting the carrier to the mount maycomprise using two or more fasteners, for example four fasteners.

In exemplary embodiments, the hole may be dimensioned to be a close fitwith the locator. The locator may be a pin. The locator may be a bolt.In such embodiments, the method may comprise screwing the bolt into thefirst and second location formations.

A hole may define the first and/or second location formation. The holedefining the first location formation may extend entirely through thecarrier, and/or the hole defining the second location formation mayextend entirely through the mount.

The first and second location formations may be positioned to be in adirection tangential to a direction of rotation of a rotor of a discbrake and generally aligned with the abutments on the carrier to supportend faces of the friction elements. Alternatively, the first and secondlocation formations may be positioned to be in a tangential direction ofrotation of a rotor and parallel to a plane defined by a face of a rotorof a disc brake, but normal abutments on the carrier to support endfaces of the friction elements.

The first and second location formations may be formed by milling orbroaching.

In a fourth aspect of the present invention there is provided a methodof mounting a carrier of a disc brake to a mount, the method comprising:providing a carrier to be mounted having a first location formation;providing a mount having a second location formation alignable with thefirst location formation; positioning a locator in the first and secondlocation formation to support the carrier in alignment with respect tothe mount so as to correctly position the carrier with respect to themount; and mounting the carrier to the mount; wherein the first and thesecond location formations are axial channels and are positioned to bein a direction parallel to a plane of rotation of a rotor of the discbrake and transverse to a direction tangential to a rotation of therotor.

The first and second location formations may be positioned to besubstantially perpendicular to a direction tangential to a rotation ofthe rotor.

The locator may remain positioned in the first and/or second locationformation during normal use of the disc brake. Alternatively, thelocator may be removed from the first and/or second location formationfor normal use.

As will be appreciated by a person skilled in the art, many of theoptional features of the third aspect may be used in combination withthe method of the fourth aspect.

In a fifth aspect of the present invention there is provided a method ofmounting a carrier of a disc brake to a mount, the method comprising:providing a carrier to be mounted having a first location formation;providing a mount having a second location formation alignable with thefirst location formation; positioning a locator in the first and secondlocation formation to support the carrier in alignment with respect tothe mount so as to correctly position the carrier with respect to themount; and mounting the carrier to the mount using two or morefasteners; wherein the first and second location formations are formedcoaxially with a bore for receiving the two or more fasteners.

The locator may remain positioned in the first and/or second locationformation during normal use of the disc brake. Alternatively, thelocator may be removed from the first and/or second location formationfor normal use.

As will be appreciated by a person skilled in the art, many of theoptional features of the third aspect may be used in combination withthe method of the fifth aspect.

In a sixth aspect of the present invention there is provided a method ofmounting a carrier of a disc brake to a mount, the method comprising:providing a carrier to be mounted having a first location formation;providing a mount having a second location formation alignable with thefirst location formation; positioning a locator in the first and secondlocation formation to support the carrier in alignment with respect tothe mount so as to correctly position the carrier with respect to themount; and mounting the carrier to the mount; wherein the first andsecond location formations are formed to be a close fit with thelocator.

The locator may remain positioned in the first and/or second locationformation during normal use of the disc brake. Alternatively, thelocator may be removed from the first and/or second location formationfor normal use.

As will be appreciated by a person skilled in the art, many of theoptional features of the third aspect may be used in combination withthe method of the sixth aspect.

In a seventh aspect of the present invention there is provided a carrieror caliper and a mount assembly, the carrier or caliper having a firstlocation formation formed therein, and the mount having a secondlocation formation formed therein, the first and second locationformations being alignable such that during assembly of the carrier orcaliper and mount a locator can be positioned in the first and secondlocation formation to enable the carrier or caliper and mount to beassembled in the correct position, and the locator can be removed fromthe assembly during normal use.

As will be appreciated by a person skilled in the art, many of theoptional features of the method of the third aspect where applicable canbe combined with the assembly of the seventh aspect.

In an eighth aspect of the present invention there is provided a carrieror caliper and a mount assembly, the carrier or caliper having a firstlocation formation formed therein, and the mount having a secondlocation formation formed therein, the first and second locationformations being alignable such that during assembly of the carrier orcaliper and mount a locator can be positioned in the first and secondlocation formation to enable the carrier or caliper and mount to beassembled in the correct position, wherein the first and the secondlocation formations are axial channels and are positioned to be in adirection parallel to a plane of rotation of a rotor of the disc brakeand transverse to a direction tangential to a rotation of the rotor.

As will be appreciated by a person skilled in the art, many of theoptional features of the method of the fourth aspect where applicablecan be combined with the assembly of the eighth aspect.

In a ninth aspect of the present invention there is provided a carrierand a mount assembly, the carrier having a first location formationformed therein, and the mount having a second location formation formedtherein, the first and second location formations being alignable suchthat during assembly of the carrier and mount a locator can bepositioned in the first and second location formation to enable thecarrier and mount to be assembled in the correct position; and theassembly comprising two or more fasteners attaching the carrier to themount, and wherein the first and second location formations are formedcoaxially with a bore for receiving the two or more fasteners.

As will be appreciated by a person skilled in the art, many of theoptional features of the method of the fifth aspect where applicable canbe combined with the assembly of the ninth aspect.

In a tenth aspect of the present invention there is provided a carrierand a mount assembly, the carrier having a first location formationformed therein, and the mount having a second location formation formedtherein, the first and second location formations being alignable suchthat during assembly of the carrier and mount a locator can bepositioned in the first and second location formation to enable thecarrier and mount to be assembled in the correct position, and whereinthe first and second location formations are formed to be a close fitwith the locator.

As will be appreciated by a person skilled in the art, many of theoptional features of the method of the sixth aspect where applicable canbe combined with the assembly of the tenth aspect.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the present invention will now be described withreference to the accompanying drawings in which:

FIG. 1 shows a perspective view of a disc brake of the prior art;

FIG. 2 shows a schematic plan view of a rotor and friction element of adisc brake of the prior art;

FIG. 3 shows a partial perspective view of a carrier and mount assemblyaccording to an embodiment of the present invention;

FIG. 4 shows a carrier and mount assembly according to anotherembodiment of the present invention;

FIG. 5 shows a carrier and mount assembly according to a furtherembodiment of the present invention;

FIG. 6 shows the carrier and mount assembly of claim 6 at anintermediate step in a method of assembly according to an embodiment ofthe present invention;

FIG. 7 shows a front view of a carrier and mount assembly according toan embodiment of the present invention;

FIG. 8 shows a perspective view of the carrier and mount assembly ofFIG. 7;

FIG. 9 shows a plan view of a carrier and mount assembly of a furtherembodiment of the present invention;

FIG. 10 shows a partial perspective view of the carrier and mount shownin FIG. 9;

FIG. 11 shows a partially sectioned perspective view of a carrier andmount according to an alternative embodiment;

FIG. 12 shows a perspective view of a carrier of the carrier shown inFIG. 11;

FIG. 13 shows a perspective view of a mount shown in FIG. 11;

FIG. 14 shows a perspective view of the carrier and mount of FIG. 11partially assembled;

FIG. 15 shows a partially sectioned carrier and mount according to afurther alternative embodiment;

FIG. 16 shows a front view of a locator of the carrier and mount of FIG.15; and

FIG. 17 shows a perspective view of a carrier and mount of FIG. 15 in anon-mounted state.

DETAILED DESCRIPTION

As required, detailed embodiments of the present invention are disclosedherein; however, it is to be understood that the disclosed embodimentsare merely exemplary of the invention that may be embodied in variousand alternative forms. The figures are not necessarily to scale; somefeatures may be exaggerated or minimized to show details of particularcomponents. Therefore, specific structural and functional detailsdisclosed herein are not to be interpreted as limiting, but merely as arepresentative basis for teaching one skilled in the art to variouslyemploy the present invention.

Referring to FIG. 3, a carrier and mount assembly of a disc brakeaccording to an embodiment of the present invention is indicatedgenerally at 10 a. Like parts are labeled by like numerals in thedescription below, but with differing suffix letters.

A carrier 12 a is positioned on a mount 24 a. In this embodiment themount is an adapter plate of the type for mounting to a drum brake. Amount of this type (mount 24 d) is shown more clearly in anotherembodiment illustrated in FIGS. 8 and 9. The mount 24 a/d has a circularcentral section 50 a/d with holes 52 a/d spaced circumferentially aroundthe central section. The holes 52 a/d can receive bolts (not shown) tobolt the mount to a mounting for a drum brake. An upper end of the mount24 a/d (as viewed in the figures) is provided with a support 54 a/d thatextends chordally each side of the central section for supporting acarrier 12 a/d.

The support 54 d comprises a planar surface 28 a that abuts a planarsurface 26 a of the carrier. The planar surfaces 26 a and 28 a arepositioned on either side of the carrier 12 a and the mount 24 a, i.e.chordally either side of an axle, and are coplanar. However, inalternative embodiments the planar surfaces 26 a, 28 a on each side ofthe carrier 12 a and mount 24 a may be angled with respect to eachother. In such embodiments the planar surfaces 26 a, 28 a at one sidemay be substantially perpendicular to a planar surfaces 26 a, 28 a atthe other side of the carrier 12 a and mount 24 a.

Referring to FIGS. 3 to 10, throughout the present detailed descriptiondirections of features of the mount 24 a, 24 b, 24 c, 24 d, 24 e and/orcarrier 12 a, 12 b, 12 c, 12 d, 12 e are referred to with respect to arotor of a disc brake, of which the carrier may be a component thereof.Direction A is a direction through an axis of rotation of a rotor of adisc brake and is substantially perpendicular to a plane substantiallyparallel to a planar face of the rotor, referring to FIG. 8, in thisembodiment the rotor (not shown) of a disc brake will be positioned tobe in a plane substantially parallel to the plane defined by thecircular central section 50 d. Direction T is a direction tangential toa circle described by rotation of a rotor of a disc brake (which in theembodiment shown in FIG. 8 is also tangential to the central circularsection 50 d) and generally parallel or aligned with a direction ofinsertion or removal of a friction element into or from the carrier.

Referring to FIGS. 7 and 8, one friction element is inserted into one ofan upper rectangular receiving region or window 56 d on each axial sideof the carrier, and the direction of insertion or removal of a frictionelement is, in this embodiment, aligned with two opposing sides 58 d ofthe rectangular receiving region 56 d and is indicated in FIG. 8 byarrow I. Direction R is a direction substantially perpendicular to bothof the axes defined by direction A and direction T respectively (i.e. isgenerally aligned with a width of the carrier).

A location formation, in this embodiment a groove 32 a, is formed in theplanar surface 26 a of the carrier and a location formation, in thisembodiment a groove 30 a is formed in the planar surface 28 a of themount 24 a. The grooves 30 a, 32 a are linear, longitudinal grooves eachwith a semi-circular cross section. The grooves 30 a, 32 a extend in thedirection R. In this embodiment, the groove 30 a, 32 a in the carrierand the mount are positioned such that when the carrier is correctlypositioned with respect to the mount the grooves are coaxially alignedand form a conjoined location formation. In this embodiment, theconjoined location formation is a channel with a circular cross section.

A seat 34 a is machined on either side of the groove 30 a and the groove32 a. Such a machined seat 34 a provides a surface profile and roughnesscorrect for more accurate alignment of the two grooves 30 a and 32 a,and consequently more accurate alignment of the carrier with respect tothe mount.

To attach the carrier 12 a to the mount 24 a, the carrier is correctlypositioned with respect to the mount, such that the groove 30 a of themount is aligned with the groove 32 a of the carrier. A locator, in thisembodiment a dowel (not shown in FIG. 3), is then positioned in theconjoined locator channel 31 a. The dowel is a close fit to the locatorchannel 31 a, a close fit may equate to a maximum clearance of 0.1 mm.The carrier is then attached to the mount using fasteners (not shown inFIG. 3), where in this embodiment the fasteners are bolts. The boltsscrew from underneath the mount, with respect to the orientation of thecarrier and mount assembly 10 a shown in FIG. 3, into the carrier. Inalternative embodiments, any other suitable method of attaching thecarrier to the mount may be used, for example welding.

During the step of screwing the bolts into the mount 24 a and carrier 12a, the dowel maintains the carrier and mount in correct alignment inboth the direction T and the direction R. In this embodiment, the dowelis removed from the assembly ready for normal use of the carrier andmount, i.e. mounted to an axle of a vehicle. However, in alternativeembodiments the dowel may remain positioned in the conjoined channel 31a during normal use.

Alternative embodiments are shown in FIGS. 4 to 6. In these figures thecarrier and mount assemblies 10 b, 10 c are viewed from below theassembly, with respect to the positioning of the embodiment shown inFIG. 3. In these embodiments, the carrier 12 b, 12 c is positioned on amount 24 b, 24 c. A planar surface of the carrier abuts a planar surfaceof the mount 24 b, 24 c (the planar surfaces are not visible in theFigures, but the positioning of the carrier and mount is similar to thatshown in FIG. 3).

Four bores 36 b, 36 c (only two of which are visible) are formed in themount 24 b, 24 c and the carrier 12 b, 12 c each for receiving a bolt toattach the carrier to the mount. Two of the bores 36 b, 36 c arepositioned at one side of the assembly 10 b, 10 c and the other twobores (not shown in FIGS. 6 to 8) are spaced from said two bores to bepositioned at an opposite side of the assembly 10 b, 10 c (i.e. anopposite side of an axle when the mount is attached thereto). The bores36 b, 36 c longitudinally extend through the mount and carrier in thedirection T. In this embodiment, the bores 36 b, 36 c extend entirelythrough the mount 24 b, 24 c and the carrier 12 b, 12 c. When thecarrier 12 b, 12 c is positioned correctly with respect to the mount 24b, 24 c the bore formed in the carrier is coaxially aligned with thebore formed in the mount.

Two location formations (only one is shown in the figures), in theseembodiments a slot 30 b, 30 c, is formed in the mount 24 b, 24 c and thecarrier 12 b, 12 c. In these embodiments, the slot 30 b, 30 c extendsthrough both the mount 24 b, 24 c and the carrier 12 b, 12 c. Each slot30 b, 30 c is coaxially aligned with one of the four bores 36 b, 36 c.In this embodiment, the bore 36 b, 36 c is threaded for engagement witha fastener, but there is no thread provided on the slot 30 b, 30 c.

In the embodiment shown in FIG. 4 the slot 30 b is substantially oval inshape and has a greater diameter than the bore 36 b in the direction R,such that the slot protrudes from the profile of the bore at each sideof the bore in the direction R.

In the embodiment shown in FIGS. 5 and 6, the slot 30 c is substantiallyrectangular in shape and has a greater length than the diameter of thebore 36 c in the direction R, such that the slot 30 c protrudes from theprofile of the bore 36 c at each side of the bore in the direction R.

In alternative embodiments the slot may have any suitable shape that hasa directional component in a direction parallel to the plane of therotor.

Referring to FIG. 6, to mount the carrier 12 c to the mount 24 c, adowel 38 c is positioned in the slot 30 c. The dowel 38 c is a close fitto the slot 30 c. In this embodiment the dowel 38 c has a rectangularcross section, but in alternative embodiments the cross section of thedowel may be selected to correspond to the cross-section of the slot 30c.

In this embodiment, the dowel 38 c is driven through the slot 30 c asthe bolt (not shown in FIG. 6) is screwed into the bore 36 c, and exitsthrough the opposite side of a slot 30 c formed by the slot in the mountand the slot in the carrier. However, in alternative embodiments thedowel 38 c may remain in a portion (e.g. an end portion) of the slot 30c. In such embodiments, the slot 30 c may not extend entirely throughthe mount 24 c and the carrier 12 c, and instead extend entirely throughone of the mount 24 c or carrier 12 c and only partially through one ofthe carrier 12 c or mount 24 c, respectively.

To attach the carrier to the mount, the carrier is positioned on themount. The dowel is then positioned in the slot, to ensure correctalignment. A bolt is then screwed into the adjacent, slot-free bore.Subsequently, a bolt is screwed into the bore coaxial with the slot. Asthe bolt is tightened the dowel is driven through the slot. Inalternative embodiments, the bolts may be tightened in a different orderor simultaneously.

A further alternative embodiment of a carrier and mount assembly of adisc brake is indicated generally at 10 d in FIGS. 7 and 8. A carrier 12d is positioned on a mount 24 d. A planar surface of the carrier 12 dabuts a planar surface of the mount 24 d (the planar surfaces are notvisible in FIGS. 7 and 8, but the positioning of the mount with respectto the carrier is similar to that shown in FIG. 3).

A location formation, in this embodiment a hole 30 d extends entirelythrough the mount 24 d and a hole 32 d extends partially through thecarrier 12 d. The holes 30 d, 32 d are linear holes positioned to have alongitudinal length in the direction T. In this embodiment a hole 30 d,32 d is positioned on either side (i.e. each side of an axle whenattached to an axle) of the mount and the carrier. In this embodimentthe hole 30 d, 32 d is threaded, but in alternative embodiments theholes 30 d, 32 d do not have a threaded surface. When the carrier 12 dis correctly positioned on the mount 24 d the hole 30 d of the mount 24d is coaxially aligned with the hole 32 d of the carrier 12 d. Inalternative embodiments, the hole 30 d may extend partially through themount 24 d and the hole 32 d may extend entirely through the carrier 12d.

To mount the carrier 12 d to the mount 24 d, a locator, in thisembodiment a bolt 38 d is screwed into each of the holes 30 d, 32 d. Thebolt 38 d is a close fit to the holes 30 d, 32 d. The bolts or pins maybe plain or doppler (also known as “quick release”) bolts or pins thatutilize e.g. retractable ball bearing detents to releasably hold them inplace, an example of a suitable pin is available from SpecialityFasteners and Components Limited of Totnes, Devon, UK, and is of the420, 425, 620, 625, 13270 or 13275 series.

Four fasteners, in this embodiment bolts 40 d are then screwed into themount 24 d and carrier 12 d to attach the carrier 12 d to the mount 24d. In this embodiment, the bolt 38 d is then removed, but in alternativeembodiments the bolt 38 d may remain in position during use. In suchembodiments the bolt provided would be shorter in length than the boltshown in FIGS. 7 and 8.

A further embodiment is shown in FIGS. 9 and 10. In this embodiment, acarrier 12 e is positioned on a mount 24 e, such that a planar surfaceof the carrier is seated on a planar surface of the mount 24 e (thepositioning of the carrier, mount and planar surfaces is similar to thatshown in FIG. 3 so will not be explained further here).

A location formation, in this embodiment a groove 30 e is positioned ontwo sides of the mount 24 e. The two said sides of the mount 24 e areorientated in a plane having axes parallel to an axis of rotation of arotor of a disc brake and parallel to a direction tangential to arotation of the rotor of a disc brake. A groove 32 e is positioned ontwo sides of the carrier.

The grooves 30 e and 32 e are linear grooves having a longitudinallength generally in a direction T tangential to a direction of rotationof a rotor of a disc brake. In this embodiment the grooves have asemi-circular cross section, but any appropriate cross section may beprovided. In this embodiment the grooves are formed by milling.

To mount the carrier 12 e to the mount 24 e the groove 32 e of thecarrier 12 e is positioned in coaxial alignment with the groove 30 e ofthe mount 24 e. A clamp having a locator component is positioned suchthat the locator component is positioned in the grooves 30 e, 32 e, andthe carrier 12 e is clamped to the mount 24 e. Whilst the carrier 12 eis clamped to the mount 24 e, the carrier 12 e is attached to the mount24 e, for example using fasteners such as bolts.

In this embodiment, the clamp applies the clamping force in a directionsubstantially perpendicular to the location formations and substantiallyperpendicular to an axis of rotation of the rotor, i.e. in the directionR.

A further embodiment is shown in FIGS. 11 to 14. In this embodiment, acarrier 12 f is positioned on a mount 24 f, such that a planar surfaceof the carrier is seated on a planar surface of the mount 24 f (thepositioning of the carrier, mount and planar surfaces is similar to thatshown in FIG. 3 so will not be explained further here).

The mount 24 f includes four through holes 72 f, 74 f, 76 f, 78 f, andthe carrier 12 f includes four through holes 80 f, 82 f, 84 f and 86 f.When the carrier 12 f is mounted to the mount 24 f the through holes ofthe mount are coaxial with the through holes of a carrier to receive afastener (not shown in FIGS. 11 to 14). The four holes 72 f, 76 f, 74 f,78 f of the mount are arranged so that two holes are on either side of aplane defined by an axis extending substantially parallel to a directionT of insertion or removal of a friction element into or from thecarrier, and an axis of rotation of a rotor of a disc brake. The fourholes of the carrier 80 f, 82 f, 84 f, 86 f are similarly arranged.

The holes 72 f, 74 f in the mount nearest an axis of rotation of a rotor(for use with the carrier) include a section 66 f, 30 f having anenlarged diameter, and the holes 80 f, 84 f in the carrier nearest theaxis of rotation of the rotor included a section 68 f, 32 f having anenlarged diameter. The section of the carrier having the enlargeddiameter is positioned adjacent the section of the mount having anenlarged diameter when the carrier is mounted to the mount. One or moreof the narrower section of the holes 72 f, 74 f, 80 f, 82 f is threadedto mate with a fastener, which in this embodiment is a threaded bolt.The enlarged diameter section is free from thread.

A bush 68 f is positioned in the enlarged sections 68 f, 66 f on aleading side of the rotor (with respect to the usual direction ofrotation of the rotor during use), and the bush 38 f is positioned inthe enlarged sections 32 f, 30 f on the on a trailing side of the rotor(with respect to the usual direction of rotation of the rotor duringuse). The bushes 38 f, 68 f are split bushes include a chamfered endnearest the mount, i.e. a leading end during assembly. The split bushesare made from spring steel.

The bush 38 f forms a locator and the enlarged sections 30 f and 32 fform location formations. As such, the bush 38 f is formed to be atransitional fit to the enlarged sections 30 f and 32 f. In the presentembodiment, the outer diameter of the bush 38 f is substantially equalto the outer diameter of the enlarged section 30 f, 32 f, but inalternative embodiments alternative transitional fits may be used, orthe bush may have a relaxed outer diameter greater than the enlargedsection 30 f, 32 f A transitional fit may be a fit having a clearance ofbetween 0 mm and 0.04 mm.

The bush 68 f is a transitional fit to the enlarged section 68 f of thecarrier, but is a loose fit to the enlarged section 66 f of the mount 24f. In this embodiment, there is a clearance between the bush 68 f andthe enlarged section 66 f of the mount of approximately 0.07 mm, but inalternative embodiments the clearance may be greater or less than this.For example, a loose fit may refer to a fit having a clearance greaterthan 0.04 mm.

To mount the carrier 12 f to the mount 24 f, the bushes 38 f, 68 f arepositioned in the enlarged sections 32 f, 68 f of the holes 82 f, 80 f.The carrier 12 f is then seated on the mount and the bushes 38 f, 68 fare positioned in the enlarged sections 30 f, 66 f of the holes 74 f, 72f of the mount 24 f. The chamfer on the leading end of the bushes 38 f,68 f eases insertion of the bushes into the enlarged sections of themount. In the case of the bush 38 f, the chamfer on the leading endprovides a lead in to the hole that eases compression of the split bush38 f so that the bush can be more easily inserted into the enlargedsection 30 f. When in the enlarged section 30 f, the split bush expandsto have an outer diameter substantially equal to the outer diameter ofthe enlarged section 32 f of the carrier and/or of the enlarged section30 f of the carrier.

Fasteners (not shown), in the present embodiment bolts, are thenfastened through the holes 72 f, 74 f, 76 f, 78 f, 80 f 82 f, 84 f, 86 fin the carrier 12 f and mount 24 f to secure the carrier 12 f to themount 24 f.

Advantageously, providing one bush that is a transitional or tight fitto the mount and one bush that is a loose fit to the mount easesassembly of the carrier and mount assembly 10 f because alignment of thecarrier to the mount is simplified. Assembly can be further simplifiedwhen the bush 38 f is a transitional fit rather than the bush having arelaxed diameter greater than the diameter of the enlarged section.

A further embodiment is shown in FIGS. 15 to 17. In this embodiment, acarrier 12 g is positioned on a mount 24 g, such that a planar surfaceof the carrier is seated on a planar surface of the mount 24 g (thepositioning of the carrier, mount and planar surfaces is similar to thatshown in FIG. 3 so will not be explained further here).

A location formation, in this embodiment a hole 30 g is positioned onone side of the mount 24 g, i.e. to one side of a plane defined by anaxis extending substantially parallel to a direction T of insertion orremoval of a friction element into or from the carrier, and an axis ofrotation of a rotor of a disc brake. The hole 30 g extends partiallythrough the mount 24 g. A location formation, in this embodiment a hole32 g is positioned to be coaxial with hole 30 g of the mount 24 g, whenthe carrier 12 g is mounted to the mount 24 g.

A locator, in this embodiment a peg 38 g is positioned to extend intothe holes 30 g and 32 g. The diameter of the peg 38 g, and the diameterof the hole 32 g in the carrier 12 g and the diameter of the hole 30 gin the mount 24 g is such that the peg 38 g is a transitional fit to thecarrier and mount when positioned in the holes 30 g and 32 g. The peg 38g is positioned on a trailing side of the rotor.

The peg 38 g is shown in more detail in FIG. 16. The peg 38 g issubstantially cylindrical. In the present embodiment, the peg 38 g has aknurled portion 60 g extending circumferentially around the peg. In thepresent embodiment, the knurled portion 60 g is positioned in the hole32 g of the carrier 12 g, but in alternative embodiments the knurledportion 60 g may be positioned in the hole 30 g of the mount 24 g. Theknurled portion 60 g and the hole 32 g of the carrier 12 g aredimensioned such that the knurled portion is an interference fit withthe carrier 12 g when inserted in the hole 32 g. The peg 38 g includes achamfered edge 62 g, 64 g at each axial extent thereof to easepositioning of the peg 38 g in the holes 30 g and 32 g.

A hole 66 g is formed in the mount 24 g and is positioned on theopposite side to the hole 30 g of a plane defined by an axis extendingsubstantially parallel to a direction T of insertion or removal of afriction element into or from the carrier, and an axis of rotation of arotor of a disc brake. A hole 68 g is formed in the carrier 12 g and ispositioned on an opposite side to the hole 32 g of a plane defined by anaxis extending substantially parallel to a direction of insertion orremoval of a friction element into or from the carrier, and an axis ofrotation of a rotor of a disc brake. The holes 66 g and 68 g aredimensioned to be substantially the same size as the holes 30 g and 32g. This means that either hole 30 g and 32 g or holes 66 g and 68 g canbe used as location formations dependent upon which side of an axle thebrake is mounted.

To mount the carrier 12 g to the mount 24 g, the peg 38 g is positionedin the hole of the 32 g of the carrier 12 g. The carrier 12 g is thenseated on the mount and the peg 38 g is positioned in the hole 30 g ofthe mount 24 g. A fastener is then engaged with the threaded holes 78 gand 86 g positioned on an opposite side to the locator of a planedefined by an axis extending substantially parallel to a direction T ofinsertion or removal of a friction element into or from the carrier, andan axis of rotation of a rotor of a disc brake, and spaced furthest fromsaid plane. A further fastener is then engaged with the threaded holes74 g and 82 g on an opposite side to the locator of a plane defined byan axis extending substantially parallel to a direction T of insertionor removal of a friction element into or from the carrier, and an axisof rotation of a rotor of a disc brake, and spaced nearest to saidplane. Then a fastener is engaged with the holes 80 g, 72 g, 74 g, 76 gon the same side as the locator of a plane defined by an axis extendingsubstantially parallel to a direction T of insertion or removal of afriction element into or from the carrier, and an axis of rotation of arotor of a disc brake. The described method of mounting the carrier tothe mount has been found to be preferred for reducing taper pad wear.However, in alternative embodiments the fasteners may be fastened in analternative order.

Advantageously, only providing a locator on one side of the carrier andmount assembly means that assembly is eased because there is no need toalign two tight fitting locators. It has been found that the provisionof only one locator is sufficient to correctly align the mount andcarrier.

Advantageously all of the above described embodiments permit the carrierto be correctly positioned with respect to the mount in both a directionparallel to an axis of rotation of a rotor of a disc brake and in aplane parallel to a plane of a rotor of a disc brake. This means thatwhen the disc brake having said mount and carrier are mounted to an axleof a vehicle, friction elements of the disc brake are substantiallyaligned with the rotor alleviating the problem of taper pad wearassociated with disc brakes of the prior art.

In embodiments where the locator is removed, removal of the locator fornormal use can reduce the weight of the disc brake in normal use.

Furthermore, the location formations are easily machined and formed.

Although the invention has been described above with reference to one ormore preferred embodiments, it will be appreciated that various changesor modifications may be made without departing from the scope of theinvention as defined in the appended claims. For example, the grooves orholes may have any appropriate cross section. Alternatively oradditionally, the grooves may have a curved or stepped profile in alongitudinal direction.

In other embodiments, the mount may be a bracket secured by welding toan axle. In alternative embodiments, the mount may be part of a steeringknuckle on a steered axle. The carrier is shown in this embodiment asnot having a beam connecting the opposing sides 58 d of the rectangularreceiving region, but in other embodiments such a beam may be provided.

In further alternative embodiments the locator is tapered. For example,the locator may be a dowel having tapered side walls. In someembodiments the dowel may be conical in shape. In such embodiments thelocation formations may also be tapered to accommodate the taperedlocator. Advantageously, a taper can guide the locator into correctposition in the location formation, which can guide the carrier intocorrect alignment with the mount. Although the present invention isprimarily applicable to the mounting of carriers the applicant hasrecognized that the arrangements described in each of the embodimentsmay also be applicable to the mounting of calipers directly to mounts ifsuch calipers are fixed (e.g. in conjunction with an axially slidingrotor).

While exemplary embodiments are described above, it is not intended thatthese embodiments describe all possible forms of the invention. Rather,the words used in the specification are words of description rather thanlimitation, and it is understood that various changes may be madewithout departing from the spirit and scope of the invention.Additionally, the features of various implementing embodiments may becombined to form further embodiments of the invention.

What is claimed is:
 1. A carrier and mount assembly for a heavy vehicledisc brake, the assembly comprising: a carrier having a first locationformation formed therein, a mount having a second location formationformed therein, wherein the second location formation is aligned withthe first location formation, and wherein the carrier is mounted to themount via two or more fasteners that extend in a direction substantiallyparallel to a direction of insertion or removal of a friction elementinto or from the carrier; and a locator positioned in the first andsecond location formations to enable the carrier and mount to beassembled in the correct position, wherein the locator is at least aclose fit to the first and second location formations.
 2. The carrierand mount assembly according to claim 1, wherein the first locationformation and the second location formation are positioned to extend ina direction substantially parallel to a direction of insertion orremoval of a friction element into or from the carrier.
 3. The carrierand mount assembly according to claim 1, wherein only one locator isprovided in the carrier and mount assembly.
 4. The carrier and mountassembly according to claim 1, wherein the first location formation is ahole formed in the carrier and the second location formation is a holeformed in the mount, and the locator is a peg positioned in the firstlocation formation and the second location formation.
 5. The carrier andmount assembly according to claim 4, wherein the peg is an elongatecylindrical member.
 6. The carrier and mount assembly according to claim4, wherein the peg comprises a knurled portion positioned in one of thecarrier and the mount, and the knurled portion is dimensioned to be aninterference fit with the carrier.
 7. The carrier and mount assemblyaccording to claim 1, wherein the carrier comprises two holes arrangedsuch that one hole is positioned on either side of a plane defined by anaxis extending substantially parallel to a direction of insertion orremoval of a friction element into or from the carrier, and an axis ofrotation of a rotor of a disc brake, and wherein the mount comprises twoholes positioned to be substantially coaxial with the two holes of thecarrier, and wherein one of the two or more fasteners extends througheach of the holes for mounting the carrier to the mount.
 8. The carrierand mount assembly according to claim 7, wherein the carrier comprisestwo further holes arranged such that one further hole is positioned oneither side of a plane defined by an axis extending substantiallyparallel to a direction of insertion or removal of a friction elementinto or from the carrier, and an axis of rotation of a rotor of a discbrake, and wherein the mount comprises two further holes positioned tobe substantially coaxial with the two further holes of the carrier, andwherein one of the two or more fasteners extends through each of thefurther holes for mounting the carrier to the mount.
 9. The carrier andmount assembly according to claim 8, wherein the two holes, the twofurther holes, and the first and second location formations are arrangedin line in a direction substantially perpendicular to an axis ofrotation of a rotor of a disc brake, and substantially perpendicular toa direction substantially parallel to a direction of insertion orremoval of a friction element into or from the carrier.
 10. The carrierand mount assembly according to claim 9, wherein the first locationformation and the second location formation are positioned between oneof the holes and one of the further holes.
 11. The carrier and mountassembly according to claim 1, wherein the locator is a bush, and thebush extends at least partially through the first and second locationformations.
 12. The carrier and mount assembly according to claim 11,wherein the bush is a split bush.
 13. The carrier and mount assemblyaccording to claim 11, wherein an end of the bush received in the mounthas a chamfered outer edge.
 14. The carrier and mount assembly accordingto claim 11, wherein the carrier comprises two holes arranged such thatone hole is positioned on either side of a plane defined by an axisextending substantially parallel to a direction of insertion or removalof a friction element into or from the carrier, and an axis of rotationof a rotor of a disc brake, and wherein the mount comprises two holespositioned to be substantially coaxial with the two holes of thecarrier, and wherein one of the two or more fasteners extends througheach of the holes for mounting the carrier to the mount.
 15. The carrierand mount assembly according to claim 14, wherein the first locationformation is integrally formed with one of the holes in the carrier andthe second location formation is integrally formed with one of the holesin the mount.
 16. The carrier and mount assembly according to claim 15,further comprising a further bush positioned to extend at leastpartially through the other of the two holes formed in the carrier andmount.
 17. The carrier and mount assembly according to claim 16, whereinthe further bush is a loose fit to the hole in the mount.
 18. Thecarrier and mount assembly according to claim 17, wherein the carrierand the mount include two further holes positioned to be on each side ofa rotor of a disc brake.
 19. The carrier and mount assembly according toclaim 18, wherein the bushes are located in the holes nearest the rotor.20. A method of mounting a carrier of a disc brake to a mount, themethod comprising: providing a carrier to be mounted having a firstlocation formation; providing a mount having a second location formationalignable with the first location formation; positioning a locator inthe first and second location formation to support the carrier inalignment with respect to the mount so as to correctly position thecarrier with respect to the mount; and mounting the carrier to the mountusing fasteners that in a mounted position extend in a directionsubstantially parallel to a direction of insertion or removal of afriction element into or from the carrier; wherein the first and secondlocation formations are formed to be at least a close fit with thelocator.